Fabrication of Fe3O4/Au@ATP@Ag Nanorod sandwich structure for sensitive SERS quantitative detection of histamine

We have successfully prepared a highly sensitive sandwich nanosensor combined Fe 3 O 4 and [email protected] @Ag nanorods for histamine detection based on surface-enhanced Raman spectroscopy (SERS). The Fe 3 O 4 beads with –COOH served as a capture part to enrich histamine. The [email protected] @Ag core-shell nanorods functionalized with Nalpha,Nalpha-Bis(carboxymethyl)- l -lysine (AB-NTA) were then used to connect with the imidazolyl group of histamine, simultaneously the internal standard 4-aminothiophenol (4-ATP) in the core-shell structure was used as the SERS signal. PLS regression model based on concentration range 10 −3 -10 −8 mol/L showed a linear trend with R 2  = 0.9907. Our new approach can quickly and reliably determine histamine in fish sample and RAW264.7 cell lysates. This protocol for histamine extraction and SERS analysis enables the development of ultra-sensitive method for histamine detection.